And when you find someone who thinks they've proved that putting (currently) seven million metric tons of carbon dioxide into the atmosphere every year can't have any effects, have a look at what the Met Office has to say at http://www.metoffice.gov.uk/research/hadleycentre/index.html or the Royal Society at http://www.royalsoc.ac.uk/page.asp?id=6229.
Also, can we have numbering on the posts? It's fine when there's only a few posts, but this is getting confusing now.
1) There are possibly some (very rare) occasions when the earth has warmed very rapidly before. See http://www.whoi.edu/institutes/occi/viewArticle.do?id=9986. This is worrying research, since it shows that feedbacks may produce larger swings in temperature than previously thought.
2) The likely effects of global warming are disastrous. Take a look at this IPCC's Policy-maker's Summary: http://www.grida.no/climate/ipcc_tar/wg2/005.htm.
Some global warming is inevitable. Reducing carbon emissions now, however, will let us avoid the worst.
Also, Martin, the IPCC is funded by the UN and written by publishing climatologists - less partial than reports by the Exxon-funded AEI and written by White House PR men, surely?